Flywheel overload releasing band clutch

ABSTRACT

A flywheel overload releasing band clutch employing a leveractuated band clutch which clamps on two equal diameter concentric drums, one attached to the flywheel and the other attached to the flywheel shaft.

United States Patent [72] Inventor Emerson Bradlord Donnell, Jr. [56]References Cited Hillsborough Township, Somerset 0)., NJ. UNITED STATESPATENTS P 869'676 1,167,010 1/1916 Neel 192 80 [22] F1led Oct. 27, I9691,847,882 3/1932 Long.. 64/30 (E) 21:11: Co mm 2,743,803 5/1956 Ferris64/30 (E) x g New York, ML 3,335,835 8/1967 Conlon ..l92/56 c x PrimaryExaminerAllan D. Hermann AttorneysPaul A. Rose, Gerald R. OBrien, Jr.and Aldo J. [54] FLYWHEEL OVERLOAD RELEASING BAND cozzi CLUTCH 8 Claims,4 Drawing F igs.

[52] US. Cl 192/56,

1 192/80 [51] Int. Cl ..Fl6d 43/20, ABSTRACT: A flywheel overloadreleasing band clutch em- F16d 13/10 ploying a lever-actuated bandclutch which clamps on two [50] Field of Search 192/26, 56, equaldiameter concentric drums, one attached to the 80, 150; 74/572; 64/30 Eflywheel and the other attached to the flywheel shaft.

FLYWHEEL OVERLOAID RELEASING BAND CLUTCH FIELD OF INVENTION Thisinvention relates to an improved release device for flywheels. Moreparticularly, this invention relates to a releasing band clutch for thetimely release of flywheels during overloading conditions.

THE PRIOR ART Flywheels are commonly used for such purposes asminimizing fluctuations inthe speed of rotating machine members, andreducing drive motor size by adding or substracting energy to therotating member. In instances of severe negative acceleration due tosuch failures as machine jam-ups, the flywheel inertia is limited onlyby the rate of acceleration. Such negative acceleration createspractically limitless available torque and damage often results to therotating machine member.

To prevent or reduce damage to the machine, overload devices such asshear keys, shear pins, slip clutches, and latching mechanisms are usedto connect the-flywheel to the shaft. Each of these devices, althoughserving useful purposes in certaininstances, has its disadvantages. Forexample, slip clutches heat up and/or wear out from frequent use; shearkeys and shear pins can fatigue and fail prematurely as well asrequiring considerable disassembly for replacement; and latchingmechanisms wear out from the shaking due to vibration of the flywheelwith respect to its shaft, particularly in the case of heavy flywheels.

Thus, an overload releasing device which would have minimum wear fromfrequent use, heat buildup or vibrations, as well as minimum instancesof fatigue and subsequent failure would be most suited for use inflywheels which have by high incidence of undue acceleration.

It is, accordingly, the prime object of the present invention to providea flywheel overload releasing devices which permits a flywheel to rotatefreely after a predetermined amount of torque and requires minimummaintenance and repair.

SUMMARY In accordance with the present invention, a flywheel overloadreleasing device is provided employing a concentric sup port memberrigidly secured to a rotatable shaft means upon which a flywheel isrotatably mounted, the support member being of equal diameter to theflywheel; clutch band means associated with the support member and theflywheel and mounted for engagement and disengagement against thesupport member and flywheel; clamping means for engaging the clutch bandmeans to the support member and flywheel at a predetermined tensileforce; lever means connected with the clamping means for actuating theclamping means to effect disengagement of the clutch band from thesupport member and flywheel; and lever actuating means positioned on theflywheel so as to actuate the lever means upon a predetermined slippageof the flywheel, thereby causing free rotation of the flywheel.

In another aspect of the present invention an overload 'releasing devicefor flywheels is provided employing at least two equal diameter,concentric support members mounted on rotatable shaft means upon which aflywheel is mounted, one of the support members being rigidly secured tothe shaft and one of the support members being rigidly secured to theflywheel; clutch band means associated with the concentric supportmembers and mounted for engagement and disengagement against the supportmembers; clamping means for engaging the clutch band to the supportmembers at a predetermined tensile force; lever means connected with theclamping means for actuating the clamping means to effect disengagementof the clutch band from the support members; and lever-actuating meanspositioned on the support member rigidly secured to said flywheel so asto actuate the lever means upon a predetermined slippage of theflywheel, thereby causing free rotation of the flywheel.

Reference is made to the figures of the drawings in which:

FIG. 1 is a schematic view of the preferred releasing band clutch in anengaged position;

FIG. 2 is a sectional view of the releasing band clutch of FIG. 1 takenalong lines 2-2;

FIG. 3 is a schematic view of the releasing band clutch of FIG. 1 shownin the disengaged position; and

FIG. 4 is another embodiment the releasing band clutch of the presentinvention showing a dual clamping mechanism.

DESCRIPTION In FIG. ll of the drawings, a flywheel 2 mounted on arotatable shaft 4 by a bearing (not shown), is provided with a releasingband clutch device employing two equal diameter, concentric drums 6,8mounted on the shaft. One of the drums is rigidly secured to the shaft 4(hereinafter called the shaft drum 6) by a shaft hub 5. The other drum 8is rigidly secured to the flywheel 2 (hereinafter called flywheel drum8) by bolts. The drums 6,8 although secured to the shaft 4 and flywheel2 by shaft hub 5 and bolts, respectively can be secured by othersuitable conventional means. The diameters of the drums are notcritical, the only requirement being that they are of equal diameter.For simplicity of construction,

preferably the drums are of the same diameter as the flywheel.

A metal band 10, with a composite lining 12 attached to the interior, iswrapped around both drums 6,8. From the standpoint of durability,availability and cost the preferred metal employed is steel, althoughother suitable substitutes could be employed. The composite lining 12,which is employed at the interface between the band 10 and the drums 6,8can be any, typical composite clutch and brake lining. The compositelining 12 is attached to the band 10 by conventional adhesive.Preferably, shoulder bolts 13 are employed to secure the band 10 to theshaft drum 6 to prevent the band 10 from turning with respect the shaftdrum 6.

A clamping mechanism 14 is employed to tighten the band 10 to apredetermined tensile force. Preferably, the clamping mechanism is atoggle clamping mechanism employing a spring loaded link and preferablyan eccentric shaft 19 for loading the link. The tensile force to beapplied against the flywheel drum can vary widely and a choice as to thedesired tensile force would depend upon the purpose for which thereleasing band clutch of the present invention is being employed. Alever 16 is mounted on the clamping mechanism 14 for actuating thetoggle clamping mechanism 14 to effect disengagement of the band byreleasing the clamping force created by the springs. The lever 16 isactuated by bolt heads 18 mounted on the outer surface of the flywheeldrum 8 in predetermined spaced positions. The boltheads are all mountedso as to contact the lever 16 upon a predetermined amount of slippage ofthe flywheel drum 8. Preferably the boltheads 18 are equally spacedabout the flywheel drum 8. The spacing between boltheads l8 depends uponthe amount of slippage of the flywheel drum 8 which could be tolerated.Preferably, the boltheads 18 are spaced about from 2 to about 6 inchesapart. Thus, the number of boltheads 18 on each flywheel drum would bedependent upon the diameter of the flywheel drum as well as thepermissible amount of slippage of the flywheel. Preferably, the lever 16includes a trigger 17 which is pivotably mounted thereto to allow forpossible creep between flywheel drum 8 and band 10. During normaloperation, centrifugal force holds the trigger 17 out of the path of theboltheads 18. During negative acceleration of the assembly, inertialforce throws the trigger into the path, allowing for operation of thelever against the bolt heads 18.

Alternatively, as shown in FIG. 4, the releasing band clutch of thepresent invention is provided employing two clamping mechanismspreferably mounted on the band on opposite sides and each having its ownlever for disengaging the clamping force against the flywheel drum. Thesecond lever would be mounted on its clamping mechanism so as todisengage the clamping mechanism when slippage of the flywheel drumoccurs in the opposite direction. When employing such double clampingmechanism, which can be actuated by slippage in either direction, thereleasing clutch band of the present invention operates to permit freerotation of the flywheel in instances of positive and negativeacceleration.

In another embodiment of the present invention, the clutch band isemployed against the flywheel directly without the necessity of aflywheel drum 8. A support member, such as a drum, is employed with theflywheel to provide the surface against which the releasing band clutchof the present invention operates. in such instance, the lever-actuatingmeans, such as the boltheads, are mounted on the flywheel directly.Alternatively, such embodiment can also employ a dual clamping mechanismas previously described, which would operate under positive as well asnegative accelerations.

in another embodiment of the present invention, the band 10 is securedto the flywheel and the lever-actuating means is on the shaft drumwhereby the releasing band clutch of the present invention is actuatedwhen overload slippage occurs between the band and shaft drum.

The flywheel overload releasing band clutch operates to permit aflywheel to rotate freely when positive or negative acceleration becomestoo severe and the inertia of the rotating member would otherwise createextensive damage. When the rotating machine member is in normaloperation, the flywheel overload releasing band clutch of the presentinvention is tightly engaged against the drums 6,8 by means of thetoggle clamping mechanism, and the friction created at the interface ofthe composite lining l2 and the flywheel drum 8 prevents rotation of theflywheel drum 8 with respect to band 10. This friction force issufficient to transmit normal peak loads from flywheel to shaft, butwhen a severe overload occurs, slippage takes place at this frictioninterface. As this slippage occurs, boltheads 18 pass by trigger l7actuating the lever 16 and thereby releasing the clamping force throughan eccentric shaft. With the clamping force reduced to zero, theflywheel 2 is free to coast to a stop without adding frictional heat tothe band and flywheel drums.

The flywheel and flywheel overload releasing band clutch is useful withmost any type of rotating machine where it is desired to have minimumfluctuations in speed, or reduce the size of the motor which rotates theshaft. For example, hot sheet shredders which tear warm sheets ofmaterial and spin at high revolutions per minute find flywheels mostuseful for minimizing motor size.

What I claim is:

l. A flywheel overloading releasing device comprising a concentricsupport member rigidly secured to a rotatable shaft means upon which aflywheel is rotatably mounted, said support member being of equaldiameter to said flywheel; clutch band means associated with saidsupport member and said flywheel and mounted for engagement anddisengagement against said support member and flywheel; clamping meansfor engaging said clutch band means to said support member and flywheelat a predetermined tensile force; lever means connected with saidclamping means for actuating said clamping means to effect disengagementof said clutch band from said support member and flywheel; andlever-actuating means, positioned for contact with said lever means soas to actuate said lever means upon a predetermined slippage, therebycausing free rotation of said flywheel.

2. The device of claim 1 wherein said lever-actuating means is mountedon said flywheel.

3. A flywheel overload releasing device comprising at least two equaldiameter, concentric drums mounted on rotatable shaft means upon which aflywheel is mounted, one of said drums being rigidly secured to saidshaft and one of said drums being rigidly secured to said flywheel;

clutch band means associated with said concentric drums and mounted forengagement and disengagement against said drums; clamping means forengaging said clutch band to said drums at a predetermined tensileforce;

lever means connected with said clamping means for actuating saidclamping means to effect disengagement of said clutch band from saiddrums;

and lever-actuating means positioned on said drum rigidly secured tosaid flywheel so as to actuate said lever means upon a predeterminedslippage of said flywheel, whereby causing free rotation of saidflywheel.

4. The device of claim 3 wherein said clutch band means comprises acomposite lining and a metal band.

5. The device of claim 3 wherein said clamping means comprises a toggleclamping mechanism.

6. The device of claim 5 wherein the toggle clamping mechanism comprisesa spring loaded link and an eccentric shaft for loading said link.

7. The device of claim 3 wherein said clamping means comprises twoclamping mechanisms and two lever means connected thereto to permitdisengagement of said clutch band means upon slippage of said flywheelin either direction.

8. The device of claim 3 wherein lever actuating means comprises aplurality of bolts secured to said flywheel.

1. A flywheel overloading releasing device comprising a concentricsupport member rigidly secured to a rotatable shaft means upon which aflywheel is rotatably mounted, said support member being of equaldiameter to said flywheel; clutch band means associated with saidsupport member and said flywheel and mounted for engagement anddisengagement against said support member and flywheel; clamping meansfor engaging said clutch band means to said support member and flywheelat a predetermined tensile force; lever means connected with saidclamping means for actuating said clamping means to effect disengagementof said clutch band from said supporT member and flywheel; andleveractuating means, positioned for contact with said lever means so asto actuate said lever means upon a predetermined slippage, therebycausing free rotation of said flywheel.
 2. The device of claim 1 whereinsaid lever-actuating means is mounted on said flywheel.
 3. A flywheeloverload releasing device comprising at least two equal diameter,concentric drums mounted on rotatable shaft means upon which a flywheelis mounted, one of said drums being rigidly secured to said shaft andone of said drums being rigidly secured to said flywheel; clutch bandmeans associated with said concentric drums and mounted for engagementand disengagement against said drums; clamping means for engaging saidclutch band to said drums at a predetermined tensile force; lever meansconnected with said clamping means for actuating said clamping means toeffect disengagement of said clutch band from said drums; andlever-actuating means positioned on said drum rigidly secured to saidflywheel so as to actuate said lever means upon a predetermined slippageof said flywheel, whereby causing free rotation of said flywheel.
 4. Thedevice of claim 3 wherein said clutch band means comprises a compositelining and a metal band.
 5. The device of claim 3 wherein said clampingmeans comprises a toggle clamping mechanism.
 6. The device of claim 5wherein the toggle clamping mechanism comprises a spring loaded link andan eccentric shaft for loading said link.
 7. The device of claim 3wherein said clamping means comprises two clamping mechanisms and twolever means connected thereto to permit disengagement of said clutchband means upon slippage of said flywheel in either direction.
 8. Thedevice of claim 3 wherein lever actuating means comprises a plurality ofbolts secured to said flywheel.